PLC技术讨论与未来发展————外文翻译.pdf

无锡科技职业学院毕业设计 外文翻译 外文资料 PLC technique discussion and future development Everyone knows there s only one constant in the technology world and that s change This is especially evident in the evolution of Programmable Logic Controllers PLC and their varied applications From their introduction more than 30 years ago PLCs have become the cornerstone of hundreds of thousands of control systems in a wide range of industries At heart the PLC is an industrialized computer programmed with highly specialized languages and it continues to benefit from technological advances in the computer and information technology worlds The most prominent of which is miniaturization and communications The people see in produce practice automate brought the tremendous convenience and the product quantities for people up of assurance also eased the personnel s labor strength reduce the establishment on the personnel The target control of the hard realization in many complicated production lines whole and excellent turn the best decision etc well trained operation work technical personnel or expert governor but can judge and operate easily can acquire the satisfied result The research target of the artificial intelligence makes use of the calculator exactly to carry out imitate these intelligences behavior moderating the work through person s brain and calculators with the mode that person s machine combine for resolve the very complicated problem to look for the best path In recent years smaller PLCs have been introduced in the nano and micro classes that offer features previously found only in larger PLCs This has made specifying a larger PLC just for additional features or performance and not increased I O count unnecessary as even those in the nano class are capable of Ethernet communication motion control on board PID with autotune remote connectivity and more PLCs are also now well equipped to replace stand alone process controllers in many applications due to their ability to perform functions of motion control data acquisition RTU remote telemetry unit and even some integrated HMI human machine interface functions Previously these functions often required their own purpose built controllers and software plus a separate PLC for the discrete control and interlocking 无锡科技职业学院毕业设计 外文翻译 PLC language is not we imagine of edit collected materials the language or language of Cs to carry on weaving the distance but the trapezoid diagram that the adoption is original after the electric appliances to control make the electrical engineering teacher while weaving to write the procedure very easy comprehended the PLC language and a lot of non electricity professional also very quickly know and go deep into to the PLC Is PLC one of the advantage above and only this is also one part that the people comprehend more and easily in a lot of equipmentses the people have already no longer hoped to see too many control buttons they damage not only and easily and produce the artificial error easiest small is not a main error perhaps you can still accept But lead even is a fatal error greatly is what we can t is tolerant of New technique always for bringing more safe and convenient operation for us make we a lot of problems for face on sweep but light do you understand the HMI Says the HMI here you basically not clear what it is also have no interest understanding change one inside text explains it into the touch to hold or man machine interface you knew it combines with the PLC to our larger space HMI the control not only only is reduced the control press button increase the vivid of the control more main of it is can sequence of and at can the change data input to output the feedback with data control in the temperature curve of imitate but also can keep the manifestation of view to come out And can write the function help procedure through a plait to provide the help of various what lies in one s power the one who make operate reduces the otiose error Currently the HMI factory is also more and more the function is also more and more strong the price is also more and more low the noodles of the usage are wide more and more The HMI foreground can say that think to be good very At a lot of situations the list is is a smooth movement that can t guarantee the equipments by the control of the single machine but pass the information exchanges of the equipments and equipments to attain the result that we want For example fore pack and the examination of the empress work preface we will arrive wrapping information feedback to examine the place and examine the information of the place to also want the feedback to packing Pass the information share thus to make both the chain connect becoming a total body the match of your that thus make is more close at each other attain to reflect the result that mutually flick 无锡科技职业学院毕业设计 外文翻译 The PLC correspondence has already come more more body now its value at the PLC and correspondence between PLCs can pass the communication of the information and the share of the datas to guarantee that of the equipments moderates mutually the result that arrive already to repair with each other Data conversion the adoption RS232 between PLC connect to come to the transmission data but the RS232 pick up a people and can guarantee 10 meters only of deliver the distance if in the distance of 1000 meters we can pass the RS485 to carry on the correspondence the longer distance can pass the MODEL only to carry on deliver The PLC data transmission is just to be called a form to it in a piece of and continuous address that the data of the inner part delivers the other party we the PLC of the other party passes to read data in the watch to carry on the operation If the data that data in the watch is a to establish generally that is just the general data transmission for example today of oil price rise I want to deliver the price of the oil price to lose the oil ally on board that is the share of the data But take data in the watch for an instruction procedure that controls the PLC that had the difficulty very much for example you have to control onepedestal robot to press the action work that you imagine you will draw up for it the form that a procedure combine with the data sends out to pass by The form that information transport contain single work the half a work and the difference of a workses The meaning of the single work also is to say both a can send out only but a can receive only for example a spy he can receive the designation of the superior only but can t give the superior reply A work of half is also 2 and can can send out similar to accept the data but can t send out and accept at the same time for example when you make a phone call is to can t answer the phone the other party also But whole pair works is both can send out and accept the data and can send out and accept at the same time Be like the Internet is a typical example The process that information transport also has synchronous and different step cent The data line and the clock lines are synchronous when synchronous meaning lie in sending out the data is also the data signal and the clock signals to be carry on by the CPU to send out at the same time this needs to all want the specialized clock signal each other to carry on the transmission and connect to send and is constrained the characteristics of this kind of method lies in its speed very quick but correspond work time of take up the CPU and also want to be long oppositely at the same time the technique difficulty also very big Its request lies in canting have an error margins in a 无锡科技职业学院毕业设计 外文翻译 datas deliver otherwise the whole piece according to compare the occurrence mistake this on the hardware is a bigger difficulty Applied more and more extensive in some appropriative equipmentses be like the appropriative medical treatment equipments the numerical signal equipments etc in compare the one data deliver its result is very good And the different step is an application the most extensive this receive benefit in it of technique difficulty is opposite and want to be small at the same time not need to prepare the specialized clock signal its characteristics to lie in its data is partition the long lost send out and accept be the CPU is too busy of time can grind to a stop sex to work also reduced the difficulty on the hardware the data throw to lose at the same time opposite want to be little we can pass the examination of the data to observe whether the data that we send out has the mistake or not be like strange accidentally the method tired addition and eight efficacies method etc can use to helps whether the data that we examine to send out have or not the mistake occurrence pass the feedback to carry on the discriminator A line of transmission of the information contain a string of and combine the cent of The usual PLC is 8 machines certainly also having 16 machines We can be an at the time of sending out the data a send out to the other party also can be 88 send out the data to the other party an and 8 differentiationses are also the as that we say to send out the data and combine sends out the data A speed is more and slowly but as long as 2 or three lines can solve problem and can use the telephone line to carry on the long range control But combine the oscular transmission speed is very quick of it is a string of oscular of 25600 occupy the advantage in the short distance the in view of the fact TTL electricity is even being limited by the scope of one meter generally it combine unwell used for the data transmission of the long pull thus the cost is too expensive Under a lot of circumstances we are total to like to adopt the string to combine the conversion chip to carry on deliver under this kind of circumstance not need us to carry on to depositted the machine to establish too and complicatedly but carry on the data exchanges through the data transmission instruction directly but is not a very viable way in the correspondence because the PLC of the other party must has been wait for your data exportation at the time of sending out the data it can t do other works 无锡科技职业学院毕业设计 外文翻译 When you are reading the book you hear someone knock on door you stop to start up of affair open the door and combine to continue with the one who knock on door a dialogue the telephone of this time rang you signal hint to connect a telephone after connecting the telephone through return overdo come together knock on door to have a conversation after dialogue complete you continue again to see your book this kind of circumstance we are called the interruption to it it has the authority also having sex of have the initiative the PLC had such function Its characteristics lie in us and may meet the urgently abrupt affairs in the operation process of the equipments we want to stop to start immediately up of work the whereabouts manages the more important affair this kind of circumstance is we usually meet of PLC while carry out urgent mission total will keep the current appearance first for example the address of the procedure CPU of tired add the machine data etc be like to to stick down which the book that we see is when we open the door the page or simply make a mark because we treat and would still need to continue immediately after book of see the behind The CPU always does the affair that should do according to our will but your mistake of give it an affair it also would be same to do this we must notice The interruption is not only a sometimes existing jointly with the hour several inside break break off to have the preferred Class they will carry out the interruption of the higher Class according to person s request This kind of breaks off the medium interruption to also became to break off the set The Class that certainly break off is relevant according to various resources of CPU with internal PLC also following a heap of capacity size of also relevant fasten The contents that break off has a lot of kinds for example the exterior break off correspondence in of send out and accept the interruption and settle and the clock that count break off still have the WDT to reset the interruption etc they enriched the CPU to respond to the category while handle various business Speak thus perhaps you can t comprehend the internal structure and operation orders of the interruption completely also we do a very small example to explain Each equipments always will not forget a button it also is at we meet the urgent circumstance use of that is nasty to stop the button When we meet the Human body trouble and surprised circumstances we as long as press it the machine stops all operations immediately and wait for processing the over surprised empress recover the operation again Nasty stop the internal I O of the internal CPU of the button conjunction PLC to connect up be to press button an exterior to trigger signal for 无锡科技职业学院毕业设计 外文翻译 CPU the CPU carries on to the I O to examine again being to confirm to have the exterior to trigger the signal CPU protection the spot breaks off procedure counts the machine turn the homologous exterior I O automatically in the procedure to go to also be exterior interruption procedure processing complete the procedure counts the machine to return the main procedure to continue to work Have 1 00 can what to explain is we generally would nasty stop the button of exterior break off to rise to the tallest Class thus guarantee the safety When we are work a work piece giving the PLC a signal counting PLC inner part the machine add 1 to compute us for a day of workload a count the machine and can solve problem in brief certainly they also can keep the data under the condition of dropping the electricity urging the data not to throw to lose this is also what we hope earnestly A 2005 PLC Product Focus Study from Reed Research Group pointed out factors increasingly important to users machine builders and those making the purchasing decisions The top picks for features of importance were The ability to network and do so easily Ethernet communications is leading the charge in this realm Not only are new protocols surfacing but many of the industry de facto standard serial protocols that have been used for many years are being ported to Ethernet platforms These include Modbus ModbusTCP DeviceNet Ethernet IP and Profibus Profinet Ethernet communication modules for PLCs are readily available with high speed performance and flexible protocols Also many PLC CPUs are now available with Ethernet ports on board saving I O slot space PLCs will continue to develop more sophisticated connectivity to report information to other PLCs system control systems data acquisition SCADA systems and enterprise resource planning ERP systems Additionally wireless communications will continue to gain popularity The ability to network PLC I O connections with a PC The same trends that have benefited PLC networking have migrated to the I O level Many PLC manufacturers are supporting the most accepted fieldbus networks allowing PLC I O to be distributed over large physical distances or located where it was previously considered nearly impossible This has opened the door for personal computers to interface with standard PLC I O subsystems by using interface cards typically supplied by the PLC manufacturer or a third party developer Now these challenging locations can be monitored with today a PC Where industrial grade control engines 无锡科技职业学院毕业设计 外文翻译 are not required the user can take advantage of more advanced software packages and hardware flexibility at a lower cost The ability to use universal programming software for multiple targets platforms In the past it was expected that an intelligent controller would be complex to program That is no longer the case Users are no longer just trained programmers such as design engineers or systems integrators but end users who expect easier to use software in more familiar formats The Windows based look and feel that users are familiar with on their personal computers have become the most accepted graphical user interface What began as simple relay logic emulation for programming PLCs has evolved into languages that use higher level function blocks that are much more intuitive to configure PLC manufacturers are also beginning to integrate the programming of diverse functions that allow you to learn only one package in configuring logic HMI motion control and other specialized capabilities Possibly the ultimate wish of the end user would be for a software package that could seamlessly program many manufacturers PLCs and sub systems After all Microsoft Windows operating system and applications work similarly whether installed on a Dell HP or IBM computer which makes it easier for the user The development of the higher layer needs our continuous effort to obtain The PLC emergence has already affected a few persons fully we also obtained more knowledge and precepts from the top oneexperience of the generation coming to the continuous developmentPLC technique push it toward higher wave tide 无锡科技职业学院毕业设计 外文翻译 中文翻译 PLCPLC 技术讨论与未来发展技术讨论与未来发展 众所周知 科技世界里只有一个永恒真理 那就是变化 这在可编程逻辑控 制器 PLC 及其各种应用的发展过程中尤为明显 自从三十多年前将 PLC 引 进以来 PLC 已经在广泛的工业领域中成为几十万控制系统的基础 从本质上讲 PLC 是一种用高度专业化语言编程的工业计算机 并继续受益 于计算机和信息技术领域的技术进步 它的最突出之处是小型化和通信功能 人们在生产实践中看到 自动化给人们带来了极大的便利和产品质量上的保 证 同时也减轻了人员的劳动强度 减少了人员上的编制 在许多复杂的生产过 程中难以实现的目标控制 整体优化 最佳决策等 熟练的操作工 技术人员或 专家 管理者却能够容易判断和操作 可以获得满意的效果 人工智能的研究目 标正是利用计算机来实现 模拟这些智能行为 通过人脑与计算机协调工作 以 人机结合的模式 为解决十分复杂的问题寻找最佳的途径 近年来 更小型 PLC 已经发展到纳米级和微型级 它们已具有以前只在大 型 PLC 上才有的特点 因此仅为了额外特性或性能而不是增加 I O 容量而具体 指定一个大型的 PLC 变得不必要 因为即使纳米级 PLC 也具备以太网通信 运 动控制 自动调谐的嵌入式 PID 远程连通性等更多的功能 现在 由于 PLC 能执行运动控制 数据采集 远程终端单元 RTU 甚至 一些集成人机介面 HMI 等功能 因此 PLC 在很多应用中也已配置齐全从而 替代单一的过程控制器 以前 这些功能通常要求他们自身内置实现这些功能的 控制器和软件 此外 还需要一个用于离散控制和互锁的独立的 PLC PLC 的内部包含了具有中央处理器的 CPU 并带有外部 I O 口扩展的 I O 接 口地址和存储器三大块组成 CPU 的核心是由一个或者多个累加器组成 它们 具有逻辑的数学运算能力 并能读取程序存储器的内容通过计算后去驱动相应的 存储器和 I O 接口 I O 口将内部累加器和外部的输入和输出系统连